Leveraging football accelerometer data to quantify associations between repetitive head impacts and chronic traumatic encephalopathy in males

Abstract

Chronic traumatic encephalopathy (CTE) is a neurodegenerative tauopathy associated with repetitive head impacts (RHI), but the components of RHI exposure underlying this relationship are unclear. We create a position exposure matrix (PEM), composed of American football helmet sensor data, summarized from literature review by player position and level of play. Using this PEM, we estimate measures of lifetime RHI exposure for a separate cohort of 631 football playing brain donors. Separate models examine the relationship between CTE pathology and players’ concussion count, athletic positions, years of football, and PEM-derived measures, including estimated cumulative head impacts, linear accelerations, and rotational accelerations. Only duration of play and PEM-derived measures are significantly associated with CTE pathology. Models incorporating cumulative linear or rotational acceleration have better model fit and are better predictors of CTE pathology than duration of play or cumulative head impacts alone. These findings implicate cumulative head impact intensity in CTE pathogenesis.

Linking Type and Extent of Head Trauma to Cavum Septum Pellucidum in Older Adults With and Without Alzheimer Disease and Related Dementias

“… 15 , 16 Years of RHI is a proxy for cumulative exposure to subclinical and milder impacts, but there is variability across types of exposure (i.e., different sports, sport vs blast exposure) and within sports, such as different risks associated with position or style. 21 The distinction between participants in the TES group and participants in the ADRD group with prior RHI + TBI is relatively subjective and may partly reflect evolving diagnostic frameworks. Of note, the RHI or TBI history in both the HC and ADRD cohorts, which were at times substantial, were not always known before our prospective administration of the OSU TBI-ID and BU-HIEA and therefore would not have factored into multidisciplinary consensus diagnosis.…”

Flortaucipir tau PET findings from former professional and college American football players in the DIAGNOSE CTE research project

“…In this study, the cumulative head impact index based on measurements of linear acceleration (CHII‐G) was used to estimate the lifetime cumulative g‐force that participants experienced due to football RHI. 28 , 29 CHII‐G is a composite score based on a combination of self‐reported measures of exposure, 28 projected onto data aggregated into a positional exposure matrix (PEM) based on published helmet accelerometer studies, stratified by position and level of play. 29 All participants were diagnosed through multidisciplinary diagnostic consensus conferences using the NINDS Consensus Diagnostic Criteria for TES (including the Provisional Levels of Certainty for CTE Pathology).…”

“… 28 , 29 CHII‐G is a composite score based on a combination of self‐reported measures of exposure, 28 projected onto data aggregated into a positional exposure matrix (PEM) based on published helmet accelerometer studies, stratified by position and level of play. 29 All participants were diagnosed through multidisciplinary diagnostic consensus conferences using the NINDS Consensus Diagnostic Criteria for TES (including the Provisional Levels of Certainty for CTE Pathology). 6 , 10 The consensus conference panelists included 16 clinician‐researchers (all DIAGNOSE CTE Research Project investigators) representing multiple disciplines (neurology, neuropsychology, psychiatry, neurosurgery), from seven institutions.…”

Repetitive subconcussion results in disrupted neural activity independent of concussion history

“…Concussion, or mild traumatic brain injury (mTBI), involves a complex cascade of neurochemical changes and neurological symptoms that can have life changing consequences. 1 Repetitive subconcussions were thought to be less serious, and have been largely overlooked up until recently [2][3][4] but are now considered insidious, and occur from repetitive head impacts (RHI) common in contact sports 5,6 and in military settings with occupational repetitive blast overpressure (ReBOP) exposure (e.g., explosions, small arms, heavy weapons). [7][8][9][10][11] Postmortem studies in athletes reveal that the accumulated duration of play 5,6 and total force 6 are better predictors than concussion history for the presence and severity of chronic traumatic encephalopathy (CTE), a progressive and fatal neurodegenerative tauopathy, which is distinct from concussions and persistent postconcussion symptoms (PPCS).…”